Jamming roller clutch



9,1951 w. R. BONHAM v JAMMING ROLLER CLUTCH Filed Nbv. 26, 1948 FEE . INVENTOR. Wa/zar K fioflharr? iatenteri UNITED. STATES PATENT OFFICE i V. r if. I 570,515

- JAMM Nq-RoLLnR CLUTCH W lte R. Bonham, Palo Alto, Calif. 'Application November 26, 1948, Serial No."62,109

My invention relates to means 'for: coupling and uncoupling members rotatablerelative to each other and particularly such members arranged for rotation about a common axis.

It has been well-known for many years to couple relatively rotatable members together and then to release them in response to various actuating impulses, such as mechanical motions, thermostatic devices, electrical impulses and the like. One of the environments in which such mechanisms have been employed is in connection primarily with intermittently operating struo tures. While this category is relatively large,'a suitable example is furnished by the customary automobileradiator fan. While the fan is normally operated all of the timethat its associated engine is running, it is advisable, if it can be done simply, to couple 'and uncouple the fan from the driving mechanism, either in accord: ance with the operators control, or in automatic response to some energizing impulse such as the cooling air temperature, for example, especially such temperature of the air after it has been heated by being passed through the-engine radiator core. Devices for this purpose in the past have either involved relatively intricate and expensivev clutching devices or clutching devices which require too great an operating force for a delicate energizing mechanism or are mechanically difficult to manufacture or maintain or are expensive, or involve too radical a change in the normal environment of the structure, or have other drawbacks which havegin general worked against the adoption of such mechanisms.

It is therefore an objectof my invention in the presentiinstance to provide a clutching arrangement which is generally adaptable to machinery which must be coupled and uncoupled.

Another object of my invention is to provide a-clutching mechanism especially adaptable to intermittent service not limited to but,'for example, as embodied in an automobile fan arrangement.

A further object of my invention is to provide a jamming roller clutch readily operated and released for coupling mechanisms together.

A further object of the invention is in general to improve clutching mechanisms.

An additional object of my invention is to provide an improved automotive fan clutching mechanism. V

; Other objects together with the'foregoing are attained in the embodiment of the invention il- Claims.- (01. 192-41) 2 lustrated in the accompanying drawings in which Figure 1 is for the most part a side elevation of a jamming rollerclutch mechanism installed in a typical environment, portions being broken away to disclose the interior construction.

Figure 2 is a cross-sectional view on a vertical axial plane to an enlarged scale showing a part of the structure of Figure 1.

Figure 3 is a cross-section the plane of which is indicated by the lines 3-3 of Figure 2, certain projections being disclosed in elevation.

Figure 4 is a view to an enlarged scale of one of the jamming rollers and its environment, portions being broken away to reduce the size of the figure and to disclose the interior construction.

In its preferred form the jamming roller clutch of my invention comprises driving and driven members arranged for rotation about a common axis. The driven member preferably is provided with recesses to receive a number of jamming rollers arranged with their own secondary axes parallel to the rotational axis. Each of the rollers is provided with camming projections engageable with an actuating device, for example a thermostat, so that the rollers can be revolved about their own individual secondary axes between extreme positions, in one of which the rollers couple the driving and driven members and in another of which the rollers uncouple the driving and driven members.

While it is by no means limited to installation in the environment shown, my jamming roller clutch is well. explained in that connection. There is customarily provided an automotive type engine 6 associated with a water cooling radiator 1 having a core 8. Cooling Water is circulated between the engine 6 and the radiator I by a pump 9 in the usual fashion. A cooling fan II induces a flow of air through the radiator core 8 and over the engine 6. The fan I l is driven when required by a belt I2 deriving-its power from the engine 6 and effective to rotate a pulley I3 mounted on a driving shaft I4 and connected thereto by a key IS. The pump 9 is also driven by the shaft I 4 as the shaft turns about a first or primary rotational axis II.

In accordance withmy invention, the shaft I4 at its outboard end is enlarged to provide a drum or disc I8 preferably having a hardened peripheral surface I9 and disposed generally within the compass of the fan I I. Between the drum or disc I8 and the fan pulley I3 an anti-friction bearing 2| ismounted on the driving shaft I4 and serves as a support for a driven member 22. This encompasses the driving member I8 and, because of the bearing 2|, is independently rotatable about the same axis 11. The driven member 22 is appropriately formed around its periphery to serve as an anchorage for the blades 23 of the fan and furthermore is internally formed to pro vide an interior surface 24 substantially opposite the surface IQ of the drum l8.

In order that the dri ving anddriven members, normally freely rotatable with respect to each other can be coupled together when clesired, I form the surface 24 of the driven member, not-- as a continuously curved surface, buhrathereto provide a series of pockets or journals 26, each concentric with a secondary axial-2'l parallel to the rotational axis l1 and equidistantly dispqs d. from and around the periphery of the "drum"l8i The recesses are bounded not only by the-Sur-I.

faces 24 but are likewise bounded by a planar edia .s faqez iv tm fii-t kst fi d i a rmember 221 Disposed tin ,each; ,one, ot the recesses'n is a jamming ro1ler,,. 3 l; prefer-ably comprisinga circular cylindricalLIdi sd-like member-freely rotatable within therecess aboutthe secondary axis ZL'and being regularly formed exceptfor a chordal'flat surface fibn oneside; The location ordimension .of the 'chbrdalfs lrface '32 with re spect to the axis z'l is suchthat in, one rotated position of the roller; 3 If there is no physical contact between the roller and'the' driving member l8." When therollerds-rocked-about the axis 21 in-one direction into-"a second position, there is a direct physicalcontactbetween the rollerand the driving'dru m; and when th'eroller is rocked in the opposite direction into a third position; there: is a direct physicalcontact;betweenanother part of .the roller. land the drumZ-H These= contacts are-so arranged thatoinroneidirectionof rotation, I

for example ass-shown ini-Figure 4', the JIOHBIS jam instthe d vin member. 48:120. car-ry th ir-as: sd iven; QmbQI'eZ, zsw th them:.f r. e c i 0 iQI oi-fii,5 QW 'kb ;1 Q33 E Q3 t W 1 re1 n the hst re ti no or ati nh n lereare oppg tsly cked-s0 t t-the other portionsiof each roller contact the driving member, the coupling anduncoupling movements take placein1 'the opposite directions, v That is, by

oppositely rockingfthe roller, ,thedriving and y nmembers c n be ck dether riv' i i qs nse 9 jr tatiqnfand r e d 'i -t other or can'be locked 'togetherfi'for drivingro'tation in the other direction and released inthe first sense. If the roller occupies a middle or interi mediate position, there is nodriying connection between the driving and driven members, The number of rollers arranged around the periphery of the driving member distributes the relatively high coupIing force anddivides'such forcesothat the localized stresses in the mechanism are moda erate.

In order to actuate the individual rollers ,si,-, multaneously and in accordanc with some-se lected impulse, I provideeach of them ,with a pair of eccentric cam projections and 42 re-; spectively. Each of the projections extends gen: erally axially from the face of. and is at-the ends of a diameter of its associated roller 3|.- One of the projections,.for example 41, is provided with an internal cam face 43 slanted in one vdirec tion, whereas its adjacentfcam projecti0n,,42 is provided with a slanted cam-face 44 havingthe opposite slope. The slopes of the two, camprm jections are arranged so that they,-; Wil1 simuh taneously b engaged by the edge 46 of a snap disc thermostat 41 concentrically mounted with respect to the remaining structure and secured by a central pin 48 on a closure plate 49 re- 5 movably secured to the driven member 22 by fastenings 5|. The material and location of the cover 49 are such that the temperature of the air passing through the radiator core 8 is rather promptly effective upon the snap disc thermostat lliig When the snap" disc is---i1rthe position shown in Figure 2, for example, it cams against one of the projections 4| or 42 to give all of the rollers 3l.-on e; o1;: 313118 other of their extreme positions. depending upon the design. When, however, the thermostat so 41 snaps to its symmetrical but pposite-positionsit-ireleases the cam surface 43, for example, at the same time that it presses against the cam surface 44. The rollers 3| are thus all given an increment of rotation sufficient eithertsto causetthem to enga e. or:.:to;re.lease;?de-

. def ni su l'yyt rnponly one reeti nrt sle eare or d onl b t n a-i elea t nwndnnes neaeed-r o Wf rrangementa there -i s=,aforded--,a thermally, responsive mechanism either,for en; aeipgp the-;clutch-;o1;, disengaging thecIutch. formedgbys the jamming,rollerzzmembersr In the usual installation th,

ecam surfaces 43 and and thethcrinostati idisc/ffilarejso related thatnduris 46w. t mnerature,loneratidn when air i has ing} througlif me, core" 8 {a low temperature, y ot engagefthe driving, fan'il lj i's'stationarm. As above a set'fvalue, however, the 'thermostaticjdisoi"41isnaps""into its'opposite' extreme positiod'and fin doing f'SO cams the pro jections' 4l"andj42 tofrotatethe various rollers '3I andi'to'coupl'; the driven member 2210' the drivin'g"-drum 82* This bringsthe fan" ll into operation' andf'increasesmarkedly the flow of air through 'the core-t. 'Following theoperation of they-fanfarsome; time; the temperature of 'the ambient-air should be som'e'w-hat decreased, an when itdoesricrease;the thermostat'disc 41' re=- turns tc it's-initial positicirr Nita-ting the" various jamming rollers 't'lsimultaneously and disengag-- in'g themeehanism so-"'that'the-fan--I l'is again idle? while the th'er-mosta-ti'c disc- 41 operates-automati'c'ally in response to =temperaiture;-' it *can'be manually openated or the operator-can as well cause rotation of 'the various rollers-3 I about their secondary axes to couple and uncouple the jammin roller clutchas desired or to couple the clutch-f iers automatic engagement--' in one dire'c tion ofrotation and automatic disengagement in" the otherdirection of-= -rotation--and depending upon tfie-amount of-rocking of-theindividualrollers, this particulafiCdupliiig direction can be *ineithercsensei r a i 1 In igeneralarther'eforey I haveprovideda -j amming roller clutch especially adapted for-'- in-'- stallationwini thetenvirbmn'ent shown' whereinit occupieswe ty littleomore zthan. :the (customaryspacercapable .of,itransmittingxquimny the power requiredzfonitheiindicated serviceg Furthermore, the mechanism; 'iqllitl simple in its": mechanical construetionzan'd can be madeifonith'emost .part

iiiht:r 3 :aw dfisimamlfacturingjatolerances. =.so,- that the cost of construction is low. Thermainnancies rr ominalssincezltheeentirej unitscan adilmleererlesedit-necessary,

articular.-r'd signra smcei n I claim:

1. A jamming roller clutch comprising a driving member arranged to rotaterabout a main axis, a driven member arranged to rotate about said axis, rollers carried by said driven member and rotatable about secondary axes parallel to said main axis between a first position free from said driving member and a second position engaging said driving member, eccentric cam projections extending axially from said rollers, and

means movable axially in engagement with said projections for rotating said rollers about said secondary axes.

2. A jamming roller clutch comprising a driving member arranged to rotate about a main axis, a driven member arranged to rotate about said axis, rollers carried by said driven member and rotatable about secondary axes parallel to said main axis between a first position free from said driving member and a second position engaging said driving member, eccentric cam projections extending axially from said rollers, and a thermostat mounted on said driven member and movable axially in engagement With said projections for rotating said rollers about said secondary axes.

3. A jamming roller clutch comprising a driving member arranged to rotate about a main axis, a driven member arranged to rotate about said axis, rollers carried by said driven member and rotatable about secondary axes parallel to said main axis between a first position free from said driving member and a second position engaging said driving member, cam projections extending generally axially from said rollers substantially at the diameter ends thereof, said cam projections having oppositely slanted faces, and axially movable means engageable with said faces for rotating said rollers.

4. A jamming roller clutch comprising a drivarranged in one rotated position of said rollers to clear said driving member and in another rotated position of said rollers to engage said driving member, cam projections on said rollers, and means engaging said cam projections for rotating said rollers between said rotated positions.

5. A jamming roller clutch comprising a driving member arranged to rotate about a main axis, a drum on said driving member, a driven member encompassing said drum, said driven member having internal pockets therein, rollers in said pockets and movable between a position engaging said drum and another position free from said drum, a thermostat mounted on said driven member, and means engaged by said thermostat for moving said rollers between said positions.

WALTER R. BONHAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,160,529 Pinkham Nov. 16, 1915 1,163,803 Bickford Dec. 14, 1915 1,909,831 Jensen May 16, 1933 2,214,391 Weydell Sept. 10, 1940 FOREIGN PATENTS Number Country Date 251,521 Germany Oct. 4, 1912 

